Page:Popular Science Monthly Volume 28.djvu/495

Rh the leather of which the harness is made. Recently planting or drilling machines for planting the seed have come into use, and artificial fertilizers—the product of the chemist's art—and the mechanism for distributing it over the ground. Even after the plant has begun to grow and before it is ripe, invention must often be called into play to protect it from the ravages of insects, and not a few devices, mechanical or chemical, have been called into existence for this purpose.

The ripe cotton-balls are still picked by hand, though inventors are busy with the problem of picking it by machinery. It is gathered into baskets or bags, themselves inventions, to be transported by a cart, another invention, to the gin-house, still another invention, where it comes under the operation of the gin to separate the cotton from the cotton-seed.

Would you like to know what the cotton-gin has done toward making cotton cheap, toward enabling enough to be sold for two cents to make a yard of cloth? An acre of ground is expected to produce at least one bale of cotton, which weighs four hundred pounds or over. Before the cotton-gin was invented, a man could pick about four pounds and a half of cotton from the seed in a day; so that it took a man about ninety days to separate the cotton which he could raise on an acre from the seed.

Whitney invented the cotton-gin, and with it a man could separate seventy pounds. In other words, he could do the work in six days which before took him ninety days. The invention was made less than a hundred years ago, but inventors have been busy with it ever since, improving it year by year, and now it turns out four thousand pounds a day! In other words, a single machine will do the work of about a thousand men.

As soon as the cotton is through the gin it must be pressed into bales, for the cotton is a light, bulky article which can not be transported without confinement and a great reduction of bulk. So another invention is required, the cotton-press. Some of these presses are wonderful machines. They embrace a steam-engine, a force-pump, and a hydraulic or hydrostatic press, and give a pressure of 4,000 pounds to the square inch.

The cotton-bale is surrounded by a coarse cloth called gunny-cloth, itself the product of another line of inventions, including the arts of spinning and weaving, and made by special machinery. The bale must also be hooped with iron hoops, involving again the inventions pertaining to the manufacture of iron, but in addition the machinery for rolling it into thin and narrow strips, and I think this embraces the art of rolling iron into round bars and drawing it into wire.

These hoops must at last be fastened around the bales, and that has called for the invention of peculiar fastenings called cotton-bale ties.

At length, through all these inventions, we have the cotton ready